The alliance's platform and candidate were scheduled to be announced on 17 October 2026. Ultimately, Ada Colau was announced as candidate on 12 October, in response to Gabriel Rufián's Republican Left of Catalonia and Podemos signing a separate alliance in Catalan provinces.
The political parties within the space have struggled for months to find a common platform and lead candidate. Republican Left of Catalonia (ERC)'s spokesperson in the Congress of Deputies, Gabriel Rufián, proposed a broad front of left-wing parties (either directly or through coordination) that also included peripheral nationalists such as ERC, EH Bildu and the Galician Nationalist Bloc, and was himself touted as a prospective candidate, but he rejected such possibility in September 2026. That same month, Podemos's lead candidate Irene Montero suggested standing in a single open primary of the entire left-wing space, a proposal met with both interest and scepticism by other parties. Other names that have been speculated by the media include two of Sumar's ministers (Bustinduy and Urtasun), Ada Colau (former mayor of Barcelona), and Unai Sordo (secretary general of the Workers' Commissions trade union).
The possibility of a snap general election being called over the 2026 Spanish housing protests has forced the political parties to the left of the Spanish Socialist Workers' Party to vastly accelerate their plans to select a joint candidate and establish a common platform. After a meeting of Sumar's government ministers and with Prime Minister Pedro Sánchez gathering opinions on the advisability of calling the election, 17 October 2026 was set as the date for the announcement of the Broad Front's platform and candidate.
